Field of Invention
Embodiments of the present invention relate generally to memory management. More specifically, embodiments of the present invention may provide one or more techniques for memory management in a hierarchical memory system.
Description of Related Art
Computer systems are generally employed in numerous configurations to provide a variety of computing functions. Processing speeds, system flexibility, power consumption, and size constraints are typically considered by design engineers tasked with developing computer systems and system components. Computer systems generally include a plurality of memory devices (e.g., a dual in-line memory module (DIMM) may contain 8, 16, or more memory devices, a stacked NAND flash package may contain 2, 4, or 8 NAND die) and a plurality of memory types (i.e., memory devices that may have different performance and/or power characteristics) which may be used to store data (e.g., programs and user data) and which may be accessible to other system components such as processors or peripheral devices. Such memory devices may include volatile and non-volatile memory devices.
Typically, the memory address space of a computing system is managed by a memory management system. In certain computing systems, the memory management system may dynamically allocate portions of the memory address space to programs being executed by the processors and may allocate a separate portion of the memory address space to data being used by such a program. Conversely, the memory management system may deallocate portions of the memory address space from programs when the programs are no longer being executed by the processors. The memory management system may include tables used to map virtual memory addresses that are used by the processors to the physical memory address space. These tables may include a main memory translation table (MMXT) and a translation lookaside buffer (TLB). Often the TLB contains memory mappings for memory addresses that are used more frequently than the memory addresses in the MMXT. Searching through the MMXT and/or the TLB for a memory mapping may be time consuming resulting in delayed data retrieval.
Memory systems are often arranged with a memory hierarchy. For example, certain memory may be found in registers, cache (e.g., level 1, level 2, level 3), main memory (e.g., RAM), disk storage, and so forth. As may be appreciated, some memory systems include memory types that have different operating characteristics (e.g., operate at differing speeds). However, memory management systems generally do not differentiate between types of memory in the memory system (e.g., main memory). Accordingly, such memory management systems may handle all types of memory in the same manner. Further, some memory devices in the memory systems may be accessed (e.g., read from and/or written to) a greater number of times than other memory devices in the memory systems. As such, it may be difficult for a memory management system to identify (e.g., determine) which memory devices operate at a particular speed within the memory system. Likewise, it may be difficult for a memory management system to identify which memory devices are accessed more than others.
Accordingly, embodiments of the present invention may be directed to one or more of the problems set forth above.